Journal of the New Zealand Medical Association, 29-June-2007, Vol 120 No 1257
An international surgical collaboration for the management of pulmonary artery sarcoma: a New Zealand experience
Yaso Kathiravel, David Westwood, Jeff Macemon, Harsh Singh
Primary pulmonary artery sarcomas (PAS) are extremely rare tumours of the cardiorespiratory system. Current literature advocates surgical resection as the best treatment option.1 In surgery, the best clinical outcomes are achieved when the number of patients being treated is sufficient for expertise to be maintained. Patients requiring treatment for rare conditions typically travel to specialist centres for treatment. We describe the international surgical collaboration that enabled a patient with PAS to have his tumour resected locally in New Zealand.
A 73-year-old man who was a non-smoker was referred to the respiratory physicians with a 4-month history of progressively worsening wheeze and dyspnoea. A chest radiograph revealed a left hilar lung mass suspicious of malignancy. A computerised tomography (CT) scan (Figure 1) demonstrated an endobronchial lesion in the left upper lobe with associated left upper lobe collapse. A necrotic tumour arising from the left upper lobe was biopsied during bronchoscopy.
Histology revealed a non-epithelial malignancy. Repeat CT scans and magnetic resonance imaging (MRI) over the following 6 months revealed a progressive abnormality arising in the left main pulmonary artery with distal propagation into the left lung. A presumptive diagnosis of left pulmonary artery sarcoma was made.
In view of the extensive nature of the tumour the patient received a course of radiotherapy. However, subsequent CT scans showed signs of tumour progression.
The consensus opinion amongst thoracic surgeons consulted in New Zealand and Australia was that the tumour was unresectable and that the patient should be treated palliatively. However, a further opinion from the University of Texas M D Anderson Cancer Center was sought and two surgeons with experience of treating malignant cardiac tumours were invited to perform the surgery in Christchurch.
Figure 1. Contrast enhanced CT scan of the chest. This image demonstrates a large mass that surrounds the left upper lobe bronchus extending down to the left hilum and appearing to significantly compress and invade the left pulmonary artery
The patient was placed on cardiopulmonary bypass. The left pulmonary artery at the bifurcation, including a cuff of right pulmonary artery, was excised and samples sent for frozen section. The margins showed only fibrous tissue. A pulmonary homograft was sutured to complete communication between the right pulmonary artery and the pulmonary trunk. Left pneumonectomy and lymph node sampling was performed. A pre-operative angiogram had demonstrated severe triple vessel coronary artery disease so coronary artery bypass grafting was also undertaken.
The patient made an excellent recovery and was discharged 11 days postoperatively. Histology confirmed PAS with no lymph node involvement. Follow-up investigations showed no evidence of recurrent or metastatic disease at 12 months.
Primary PAS is rare with less than 200 cases reported since Mandelstamm first described it in 1923.2 The estimated incidence of PAS is 0.001–0.03% with a slight female preponderance (1:1.3).3,4 Reported age at presentation ranges from 13–86 years with a mean age of 48 years.5
Primary PAS are malignant mesenchymal tumours that arise from the intima of the pulmonary artery with a predilection for the dorsal region of the pulmonary trunk. They generally propagate in the direction of flow with progressive obstruction of the pulmonary outflow tract. There may be direct invasion of an adjacent bronchus or pulmonary metastases may arise from tumour emboli, but extrathoracic disease is unusual.6
Clinical presentation is non-specific and typically mimics pulmonary thromboembolic disease with symptoms of dyspnoea, chest pain, cough, and haemoptysis.7 Unilateral absence of blood flow on ventilation-perfusion scans, pedunculated lesions exhibiting a “to-and-fro” motion on pulmonary angiography or lack of response to anticoagulation should raise the suspicion of PAS.
MRI with gadolinium-diethylenetriamine pentaacetic acid enhancement has been proposed as a way of distinguishing tumour from thrombus.8 PAS may also be diagnosed on histological examination of thromboendarterectomy specimens.
Only radical surgical resection improves clinical symptoms and offers the chance of prolonged survival.1 Early lesions may be completely excised using endarterectomy. However, full-thickness resection of the pulmonary artery with reconstruction of the pulmonary outflow tract provides a better margin of resection.
For patients with extensive mediastinal involvement or metastatic disease a limited tumour resection or bypass procedure may offer significant palliation and survival benefit. The prognosis is mainly dependent on local recurrence. Median length of survival without intervention is 1.5 months. Surgical resection improves survival to approximately 12 months and there is limited evidence that this may be extended by neoadjuvant and/or adjuvant irradiation and chemotherapy.7
The rarity of cardiac malignancies means that there are few surgeons with hands-on experience of their management. The best outcomes are achieved at designated specialist units with a sufficient caseload to enable expertise to be accrued.
In the case above, an attempt was initially made to send the patient to the United States. However, the New Zealand Ministry of Health was unwilling to pay for the patient to undergo surgery in Texas in view of the indeterminate length of stay (and hence cost) of the postoperative recovery period. Videoconferencing and the transmission of scans electronically permitted the case to be discussed preoperatively.
While it is not unusual for surgeons from the developed world to donate their time and skills to perform operations in developing nations, this case is a unique example of surgeons travelling to another developed country specifically to operate on a rare condition. This was only feasible due to adequate local postoperative care provision, including the presence of a cardiac intensive care unit.
The pulmonary homograft was obtainable within New Zealand and since this was not a novel procedure local ethical approval was not required. Recognition of the visiting surgeons’ qualifications by the Medical Council of New Zealand was also necessary for them to obtain registration and indemnity insurance.
The major advantage of undertaking the procedure locally was that the patient obtained access to potentially curative surgery when previously he had been only assigned palliative treatment. The utilisation of local resources also minimised costs while the local cardiothoracic surgeons were presented with an exceptional learning opportunity. The drawbacks for the visiting surgeons were the unavailability of their usual operating team and the short duration of their stay in New Zealand. As a result, the patient was aware that the visiting specialists would only be available for the first 48 hours postoperatively.
Overall, this case suggests that in the era of globalisation there should be an emphasis placed on the development of internationally acceptable protocols for the treatment of rare conditions with improved local access to overseas surgical expertise.
Author information: Yaso Kathiravel, Registrar; David A Westwood, Registrar; Jeff B Macemon, Registrar; Harsh P Singh, Consultant; Department of Cardiothoracic Surgery, Christchurch Public Hospital, Christchurch
Acknowledgements: No external financial support was received with this project.
Correspondence: Harsh Singh, Department of Cardiothoracic Surgery, Christchurch Public Hospital, Private Bag 4710, Christchurch. Fax: (03) 364 1361; email: email@example.com
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